The Pentagon is demanding that online whistle-blower WikiLeaks turn over its trove of tens of thousands of leaked U.S. government documents and delete them from its website and records.

WASHINGTON—The Pentagon is demanding that online whistle-blower WikiLeaks turn over its trove of tens of thousands of leaked U.S. government documents and delete them from its website and records.

Pentagon press secretary Geoff Morrell did not say what efforts the Department of Defense might be able to take to compel WikiLeaks to comply. He told a news press conference Thursday that, at this point, the Pentagon is asking WikiLeaks "to do the right thing."

"The defence department demands that WikiLeaks return immediately to the U.S. government all versions of documents obtained directly or indirectly from the Department of Defense databases or records," Morrell said.

WikiLeaks posted nearly 77,000 classified military and other documents, mostly raw intelligence reports from Afghanistan, on its website July 25. The website has reportedly withheld another 15,000 similar documents, and may publish them as well.

Publication of the first cache of documents has "already threatened the safety of our troops, our allies and Afghan citizens who are working with us to help bring about peace and stability in that part of the world," Morrell said.

"Public disclosure of additional defence department classified information can only make the damage worse," he said.

The WikiLeaks' website "constitutes a brazen solicitation to U.S. government officials, including our military, to break the law," Morrell said. "WikiLeaks' assertion that submitting confidential material to WikiLeaks is safe, easy and protected by law is materially false and misleading."

So, he said, the Pentagon also "demands that WikiLeaks discontinue any solicitation of this type."

WikiLeaks also is believed to have an additional 15,000 documents that it is withholding for review, reportedly so U.S. government officials can go through them and ensure no innocent people will be identified. Morrell denied the Pentagon was ever asked to vet the documents.

WikiLeaks has posted a huge encrypted file named "Insurance" to its website, sparking speculation that those behind the organization may be prepared to release more classified information if authorities interfere with them.

Bloggers have noted that it is 20 times larger than the batch of 77,000 documents; there is speculation that the file could be a way of threatening to disclose more information if WikiLeaks' staffers were detained or if the site was attacked, although the organization itself has kept mum.

Asked if the military department has any authority to force WikiLeaks' hand, Morrell said, "We will cross the next bridge when we come to it."

"If doing the right thing is not good enough for them, then we will figure out what other alternatives we have to compel them to do the right thing — let me leave it at that," Morrell said, noting that the FBI and Justice Department are investigating the leaks.